This invention relates to lifting apparatuses.
The weight limit of a load which a lifting apparatus can safely move up and down is determined by the mechanical structure of the lifting apparatus. Accordingly, heretofore it has been inevitable that the weight limit is obtained in advance so that only the loads whose weights are lighter than the weight limit thus determined are lifted by the lifting apparatus. That is, the conventional lifting apparatus is disadvantageous in that it takes time and labor to weigh loads which are to be lifted by the conventional lifting apparatus. If a load which is heavier than the weight limit is lifted by the lifting apparatus by mistake, it will cause a dangerous accident and shorten the service life of the lifting apparatus.
Furthermore, it has been strongly demanded in the art to provide a device which can be employed in various lifting apparatuses by readily changing the weight limit according to the allowable weights thereof.